It has been known for quite some time that electrical motor nerve impulses directly result in muscle contraction. Resultantly, considerable research effort has been extended toward measurement of these electrical impulses for their direct use in situations wherein physical challenges thwart normal human skeletomuscular control. Although this research has become extremely fruitful in the diagnostic area of electromyography, use of these electrical nerve impulses for control of electrical or mechanical devices has met overwhelming obstacles. The electrical impulses are extremely low potentials, and are insulated in the body by myelin sheath. Resultantly, the reliability and useful dynamic range of these signals are poor. Being largely intermuscular, high-quality electrical motor nerve impulses (electromyography, or EMG pulses) have remained primarily accessible through use of needles, a practice made unpopular by pain.
In response to these nerve impulses, muscles emit mechanical noise, at an amplitude roughly equivalent to the force exerted. This correlation has resulted in limited use of acoustic information for diagnostic or replicative purposes, such as that shown by U.S. Pat. No. 4,748,987 “Acoustic Myography”. Due to the extreme relative weakness of these resultant acoustic pulses against the environment, however, little use has been found for electrical/acoustic correlation.
High-quality motor nerve impulses, however, are in high demand for many applications, especially diagnostic and control. A need exists for a technique whereby high-quality motor nerve impulses may be externally quantified and qualified.